Pulverizing machine



July 1927 P. A. HIRSCH PULVERIZING MACHINE Filed Nov. 20. 1924 4 Sheets-Sheet l "WE/ ran: 11d 9- H-l'rsolu a QMMJLATmMErs" July 1927' P. A. HIRSCH PULVERIZING MACHINE Filed Nov. 20. 1924 4 Sheets-Sheet 2 INVENTOR:

BY W.

Z: 4 0 ll. A TTORNEVS.

Jul 26 1927.

y P. A. HIRSCH PULVERIZING MACHINE 4 Shets-Sheet 5 Filed Nov. 20. 1924 IIIl/lllll'llllllIlllllllllll v uml.l.nlllrllallllllalrlll 13W. Kmu .24 M lnrmm/ns,

July 1927' P. A. HIRSCH PULVERIZING MACHINE Filed Nov. 20. 1924 4 Sheets-Sheet 4 i m/molmns.

Patented July 26, 1927. l *7 UNITED STATES PATENT OFFICE.

PAUL ARTHUR HIRSCII, OF NEW YORK, N. Y., ASSIGNOR TO FURNACE ENGINEERING COMPANY, INC., OF NEW YORK, N. Y., A CORPURATIO'N OF NEW YORK.

, PULVEIRIZING MACHINE.

Application filed November 20, 1924. Serial No. 751,119.

This invention is a pulvcrizing machine, having reference particularly to the pulverizing oi. coal, or other fuels or materials,.to an extreme degree o't reduction. The invention is herein shown embodied in a type of pulverizing machine having a chambered casing, with an operating shaft therein, and impact beaters or paddles revolved by the shaft. while axial air flow causes progressive advance of the material being reduced; although features of the present invention may be otherwise embodied. The illustrated design of pulverizing machine is adaptable for very fine reduction of coal, for example, for direct feed to the fire or furnace in suspension in air. A prior pulveriz-er ot the type and for the purpose refer ed to, is illustrated in my Patent No. 1,fit79,54c oi January 1, 192%; the present invention lDGHIQ ID some aspects an improvement on said prior patent and being in other aspects directed to independently useful features of invention.

One of the main objects of the present invention is to permit substantial increase of speed, as compared with speeds heretofore possible, giving maximum output or capacity with minimum floor space, and superior pulverization. Fairly rapid speeds have already been attained in pulverizers of this class, but the matter oi? securing extreme speeds raises distinct problems in respect to operativen-css, etliciency, consumption ct power etc. which have not heretolore been overcome until solved by the present invention. he machine herein described affords a very line and uniform degree of pulverization. It gives large capacity with relative low power consumption. At the same time wear is minimized and the life of the machine prolonged. Its small size and floor spacemake it available in places with restricted available space. Other and further objects and advantages of the present invention will be explained in the hereinafter following description of an illustrative embodim-entthereof, or will be apparent to those skilled in the art. To the attainment of the objects and advantages referred to the present invention consists in the novel method and machine. and the novel features of operation. combination, arrangement and construction herein illustrated or described.

In the accompanying drawings Fig. 1 is a side elevation of a pulverizing machine illustrating the present invention, the same partly broken away to show the interior parts in section.

Fig. 2 is a right hand elevation partly in section on the line 22 of Fig. 1.

Fig. 3 is a right hand elevation section on the line 33 of Fig. 1.

Fig. 4 is a view corresponding with a part of Fig. 2 showing a modified construction. I

Fig. 5 is a right hand elevation, partly in transverse section, of a modified construction.

Fig. 6 is an elevation and section similar to part of Fig. 5 showing a further modified structure.

Fig. 7 is a View similar to Fig. 1 showing a modified form of machine.

Fig. 8 is a right hand elevation partly in section on the line 8--8 of Fig. 7.

Fig. 9 is a View similar to Fig. 7 showing the same general type of machine, with modifications.

Fig. 10 is a partial view similar to Fig. 7, with certain modifications.

Referring in detail to the illustrated structure, Fig. 1 shows a pulverizing machine of partly in a horizontal type, although it could as well be vertical as in my Patent 1,479,541. Mounted on a base piece 11 is shown a cylin' drical drum or casing 12, preferably fired against rotation. The drum may be con structed in halves, the top half connected. to the lower half by a hinge 13 and permanently secured in place by bolts. The lower right hand part of the casing is shown as having a dropped extension 1.4: in which certain foreign matter may be collected as will be described. a tube or receptacle 15 being attached to the extension. and having a removable covcr 16 by which the foreign matter may be removed from time to time. The drum or casing, encloses a chamber or chambers and is shown as lined with a steel cylinder 17, which lining is perforated with a hole 18 above the extension 14, to permit heavy matter to be discharged.

The drum at its right end is closed by a circular end wall or casting or head 19 having a central or axial opening 20 by which the material to be pulverized can enter the chamber within the drum. The head 19 is shown formed with an extension 21 containing a receptacle or passage 22 for the roception and discharge of foreign matter, such as bits of iron, accompanying the entering fuel. The passage 22 is open and freely discharges the foreign matter, and at the same time admits air to the drum, which however may be regulated by a door or damper over the exit of the passage.

The extension 21 of the head 19 is shown as giving support to one of the bearings 24 of the operating shaft 25, the other end of the shaft having a similar bearing 26 supported on a fixed part as will be described. The shaft is shown provided witha cone pulley 27 at its right end by which it drives certain devices to be rcferred to, and at its left end the shaft has-an extension 28 by which it maybe driven 111 any manner, through belt and pulley, direct coupled motor. turbine orthe like.

The left or discharge end of thedrum shown as closed by anend wall orhead. 29 havin g a central or axial opening 30 through which the pulverized materials and air may pass from the drum. Preferably the pulverizing is done inside the drum, while the draft for the progressive advance of the air and materials is provided by a suction fan or blower located beyond the drum. For this purpose a fan casing 31 isshown, which may be partly integral with the head 29. The fan casing has a lateral extension 33 upon which the shaft bearing 26 is mounted as before stated. The fan casing has also a peripheral extension 34. formed with a tangential passage or exit opening 35 by which the materials are blown out of the apparatus. The exit extension 34: is flanged and may be coupled with suitable pipes for conducting the air and pulverized material to a furnace or elsewhere.

The infeed of the fuel may be by a hopper 37. This may be formed as a separate casting, mounted upon the head 19' and its oxtension 21. The hopper is seen in sectional elevation in F 3. It may have an upper deflector or inclined flange 38 preventing heavy n'iatters, such as scraps of iron, from passing directly into the pulverizing chambers. The hopper casting is also formed with a curved flange or apron 39 extending over the shaft and downwardly at the two sides so as to protect the shaft, and to cause the discharge of heavy matters into the passage 22 beneath. An upward lip or flange 40 on the apron 39 assists the exclusion of heavy pieces from the interior.

Any type of regulable infeeding device may be employed, to be located at 42, and this may be driven, through reduction gearing, by a pulley 43 and belt 41-1. The pulley a3 may be a cone pulley cooperating with the cone pulley 27, and the belt 44 may be ad justable on said pulleys by belt shifter 45 sliding alonga bracket 4:6 and controlled by an adjusting wheel 47 so as to regulate the rate of feed of coal or other material to the pulverizer. I

There may be a single pulverizer chamber within the drum, or a series of them, and

Fig. 1 shows a first reduction chamber 51 and a second reduction chamber 52, within which the fuel will be progressively pulverized by the fast rotating heating means mounted within each chamber upon the shaft 25. Thus the shaft is shown as having pinned or keyed. to it in each chamber a hub 5l-. on which is mounted a disk 55, around the circui'nference of which are mounted a series of peripheral heaters 01' paddles'56. Such a beater structure has been already explained in said prior patent and needs no further detailed description.

Located between the first and second pulverizing chambers 51 and 52 is shown a means for effecting a sudden obstructing of the whirling motion produced by the fast rotating paddles in chamber 51. This whirl Ol'JStlUCtOl may be in the form of a series of blade-like vanes set edgewise to the axial advance of the material and extending from or near the periphery of the chambers to or toward the shaft. Preferably the vanes 60 are relatively stationary, and they may stand radially or otherwise. The action of such vanes has been described in said prior patent. The several vanes may be mounted and interconnected. by means of a peripheral ring 61 attached to the lining 17, and an inner ring 62 loosely surrounding the shaft 25.

Beyond the second pulverizing chamber 52 andbetween it and the fan casing is shown another set of obstructing vanes 65, with an outer ring 66 interconnecting them. These have a special function herein, in addition to the function possessed by the vanes 60; this to be explained more fully hereinafter.

It will be noticed that within and between the pulverizing chambers there are no annular or other division walls or so-called diaphragms, nor any substantial obstruction to the axial progress of the materials, between the axial entrance aperture 20 in thehead l9 and the axial exit aperture 30 in the head 29. This aperture 30 is of considerably less diameter than the pulverizing chambers, and of less diameter eventhan that of the pulverizing elements. that is, the diameter from tip to tip of the paddles. In these and other respects to be explained the present invention is materially different from said prior patent and other prior structures of which I am familiar. The aperture 30, indeed, is shown of such small diameter that materials progressing through it pass into the interior of the rotary fan structure, an important consideration.

The fan chamber 32 may he of varying diameters, being shown of substantially the diameter of the main casing or drum, but

the fan 70 is shown of considerably smaller diameter, for reasons to be more fully described. The fan 70 is mounted on a hub 71 keyed to the shaft 25, or to the reduced extension 28 thereof, and in the form shown comprises spol-Ies 72, of which there may be two series, their outer ends supporting annular plates 73 which directly carry the fan blades 74. An important .feature is that the fan blades are preferably not radial as in prior structure, but have their outer extremities slanted backwardly from the direction of rotation. The tilt is shown in Fig. 2 as approximately 60 from the radius, although it might be greater or less. Toe tilt of the fan blades should preferably be between 25 and 75, but these limits give inferior ac tion, and in practise I have found the best tilt to be about or between 45 and 60 from the radius. The fan blades are shown in his. as compr two ScllGS of short flat ing from the high centrifugal force.

The fan blades 74: instead of being flat as in Fig. 2 may be advantageously constructed with a camber or curved form as indicated at "I in Fig. t. In this case the angle or lead of the blades should be measured as the angle between the radius and a straight line subtending the concave side of the blade.

One of the important features hereof is the en'iployment of a suction fan, such as just described, arranged for causing efficient axial progress of the air and pulverized material, yet involving low consumption of power notwithstanding the excessively high speed of the shaft to which the fan is di rer ly at tached. A fan of ordinary design, or of full diameter, would. be disadvantageous or even fatal to the proper action of the yn'esent machine, with its excessive rotary speed, and necessarily high suction or pressure. A very low pressure fan or blower is an important feature, in combination with means to cause the high pressure whirling matters to be diverted to the contracted outlet. because thus the maximum interior centrifugal pressure, and hence high pulverizing action, are maintained, where an excessive suction force would detract from the best conditions. i

In the present machine the pressure and suction produced by the fan, and the power consitmiied, are maintained at a low point, by two features. The first of these is the substantial reduction of the diameter of the fan as compared with fans usually employed in pulverizing machines of the type referred to. The fan herein shown is characterized as having an outside diameter of its rotary pa ts substantially not more than about three qu rters of the outside or tip diameter of the transverse section of certain livery.

The second mode of reducing the degec of suction and power consumption of the fan is by the tipping back of the fan blades, as described, namely, to an angle preferably well between and 75 from the radius, as sutticiently illustrated in Figs. 2! an A fan so construct-ed is adequately etlect-ive in action. The air and materials delivered to the interior of the fan are thrown or maintained in high speed whirling action,

and the mixture is del' ered tangentially through the fan casing exit The high speed of rotation usually causes a severe centrifugal strain upon the parts. The direction in which the blades are tilted, as

seen in Fig. 2, causes air pressure upon the blades toward the center, with a tendency to oppose the centrifugal force. Due to the stout structure of the parts of the fan, and their rigid interconnection, preferably by rivets, the fan hereof is extremely durable, 0

Eat the same time it is capable of effectively driving the air and n'iaterials around within the fan casing and out through the tangential discharge.

Reference will now be made to the modifications of Fi ns. 5 and 6; that of Figs. 7 and 8 to be lert to a later point as describing an extensively different embodiment from Figs. 1 to 6. Fig. 5 may be consider-ed as showing a right hand elevation, partly in the left side shows a modified form of Whirl obstructing blades 67, which instead of be ing radial as are the blades in Fig. l,

- are curved or CODCtlW-(l toward the direction of rotation of the reducing elements, indicated by the arrow. in Fig 6 this curvature is increased to such an ent that each of the whirl obstriurting blades 08 is sub stantially of spiral form. in ehher case the tendency of the materials being rapidly whirled near the periphery is to be thrown toward the center upon striking the blades. The radial blades of F i will give this result to an effective extent, and the forms of ll 5 and 6 to an increased extent. th assisting the drawing inwardly of the whirling matters, as is necessary to enable their delivery through the contracted aperture 30 into the fan. While the modified. structures of Figs. 5 and 6 are thus particulr -i adaptable for use immediately preceding the fan chamber, they may be used also to replace the blades between the two pulverizing chambers, Fig. 5 also indicates one of a number of possible modifications of the pulverizing elements in each chamber, the disk 57 being of larger diameter than the disk 553 shown in Fig. 1, and the beating elements 58 being shown as of smaller size and fixed against pivotal movement.

The operation of the apparatus so far described may be substantially as follows. Crushed coal or other material is introduced into the hopper 37 at a measured r: te, in accordance with the desired rate of corn sumption, the proportion of air to be suitably regulated in accordance therewith. The air inflow through the hopper and through the passage 22 carries the fuel through the central aperture in the head 19 and thus into the first pulverizing chamber 51. Pieces of metal which are not separated out in the hopper and discharged by passage 22 will. be thrown by centrifugal force from the first chamber through the lining aperture 18 into the discharge receptacle 15, and so removed. Within the first chamber the entering fuel is acted upon by the pulveri'zing means, in this case being struck by the paddles, and so initially reduced, and the reduced materials and air within the chamber are maintained in a very high state of rotation, and henceunder a centrifugal pressure which keeps them near to the casing lining. Progressive attrition continues as the particles of material are act-ed upon by the paddles, the action depending not merely upon delivered blows but also upon a surface rubbing action, under pressure. The reducing action is also progressive in an axial direction as the axial flow causes gradual advancing travel of the whirling matters.

As already stated one of the features hereof is excessively high speed or rotation, not heretofore attained. The practical speed. can not conveniently be stated in terms of angular motion, inasmuch as pulveriing machines are made of varying sizes, with pro portionately lower rotary speeds in the larger sizes Vith this invention, however, existing speed may be increased from 25% to 100%, for example a former peripheral speed of 225 feet per second can be increased to 280 feet per second or more, and even as high as 400 feet per second, or more, such speeds being prohibitive with heretofore known pulverizers. As an example a pulverizer with 24 paddle diameter, formerly operated at about 1100 to 1800 R. P. M. has been with this invention speeded up to 2500 R. P. M. or more, and even to 3600 R. P. M. The higher speed gives in itself an increased pulverizing action, and produces also a greatly increased centrifugal force, resultingin excessive centrifugal pressure through the pulverizing chambers. It is well known that centrifugal force increases as the square of the rotary speed, so thatudouble' speed would involve quadruple centrifugal force. Due to this extreme centrifugal force, minute particles which heretofore have merely been carried around suspended in the air, can be thrown outwardly by centrifugal force, and thus caused to strike the lining of the casin and to travel along in contact with it, greatly increasing the abrading and reducing action. The material speed increase therefore results in greater pulverizing action, not only between the particles of fuel and the paddles, butbetween the fuel and the casing. Thus is made apparent the advantage of the greatly increased speeds of rotation made available by this invention. Much finer and more uniform pulverization is attainable. Not only are better pulverization and greater output attained with the present invention, but increased life, as the wearing away of the paddles is reduced,the wear being substantially transferred to the casing lining, a cheap and easily replaced element.

The whirling materials in passing from the first to the second pulverizing chamber are cmnpelled to pass between the fixed whirl obstructing vanes 60. These vanes are arranged to permit unimpeded axial flow, while abruptly stopping the whirling action. These elements not merely cause a very effective additional pulverizing action, due to the impact of the particles upon the'vanes, and the attrition as the particles travel along the vanes, but also to a process of exclusion, by which the relatively heavier particles are caught up in eddies and thrown back into the first pulverizing chamber, as more fully described in my said prior patent. An additional resulting action is that due to the entry of the axially traveling materials into the second pulverizing chamber, wherein they are suddenly thrown from a zero speed of rotation to the full speed of the reducing elements or paddles in the second chamber. The pulverizing action in the second chamber is analogous to that in the first, the pulverizing action continuing progressively.

The high centrifugal pressure in the air and n'iaterials being reduced is maintained throughout the entire travel through the two reducing chan'ibers. This is due to the absence of diaphragms or restricted passages between the chambers. There is no element substantially impeding the axial progress along the periphery from the inlet 20 to the outlet thus differing from prior structures, in which annular diaphragms impair the peripheral pressure, and the high suction fan further reduces it. At the outlet 30 herein. however, is the diaphragm orhead 29 with the restricted opening 30 into the fan chamber, and this presents a substantial problem in the necessity of drawing inwardly the fast whirling materials held forcibly outward by theextreme centrifugal pressure, and without impairing the action. Accordloo final pulverizing chamber and the restricted outlet aperture 80. .ihe combination of the high speed pulverizing elements, the rela tively small aperture at the outlet end, and

the whirl obstructing blades or equivalent between, gives the desired result, since the highly energised whirling matters as they advance axially into the spaces between the blades are caused thereby to spread inwardly along the spaces between the blades, the whirling energy of the materials being converted into centripetal motion, so that the products passing progressively trom the linal pulverizing chamber are readily caused to draw inwardly and to pass through the contracted opening 30 into engagen'ient with the tan.

Thus the described, apparatus accomplishes the main object of the invention, permitting excessively high speeds ot rotat on without in'ipairing the proper coordination and operation or the parts, includingtl'ie necessary progress of the air and pulver zed materials from the reducing chambers nto the fan chamber. .lhe principle of utilizing the dynamic energy of the whirling matters to bring them invv'ard from the perip iery to the necessary discharge point 11 17 be embodied in various ways. Thus 5 shows curved blades (57 between the final pulverizing chamber and the aperture leading to the tan; while Fig. 6 shows spiral blades, which not merely deflect but actually cam inwardly the whirling materials so that they are readily d schargeahle thro. 1 the aperture 30. El 7 and e, as will later be described, show a yet dillierent means, not embodying whirl. restricting elements, for causing the dynamic energy of the whirling materials to bring the same inwardly suili- :icntly for discharge into the interior o the fan.

An end wall, such as or equivalent, with its contraced aperture between the linal pulverizing chamber and the fan chamher, is an essential to the proper working or the high speed machine. The wall acts like a dam which the high pressure peripherally whirling materials are confined, Vdithout any restriction atthis point the materials would progress rapidly from the casing and be discharged, making high centrit'ugal pressure impossible. I find that in order to obtain the finest degree of pulveri from an exterior hopper lO-l.

zation high internal pressure should be maintained along the entire length of the recucing chambers. The casing wall is seen to be cylindrical and at'each end is an apertur-ed wall, confining the materials peripherally, so that the high centrifugal pressure may be substantially uniform from end to end. This condition, and the need of the barrier or wall 29, creates tee dii'i culty of securing the passage of the materials from their peripheral position into the tan chamber, which diliiculty, already explained, is overcome by the vanes or blades 65, serving as a diverting means,and allowing easy transition from the high pressure conditions within the pulverizing chambers to the low pressure conditions in the tan chamber. Such low pressure conditions in the tan chamber are of great practical desirability and enable the employment of a tan having small power consumption. The structure of the tan, and its small diameter, have already been referred to. This cooperates with the small diameter opening 80 between the :tan chamber and the main casing, since the materials passing through the opening will thereby be delivered into the interior of the tan and thrown into high speed rotation, and thus delivered tangentially from the -lan easing into the pipes leading to a furnace, a place of storage, or the like. The fan, owing to its small diameter and the described tilt ot its blades, will effectively rotate and tangentially deliver the air and pulverized fuel, and this with minimum consumption of power, notwithstanding the high rotary speed of the shaft carrying the fan.

Figs. 7 and 8 show a modified PlllVEllZQl structure embodying the same underlying principles. as the structure described. The "ase "r00 supports a casing 101., having a first end wall or head 102 formed with a cei'itral aperture 103, tl'irough which t'uel or other material. is passed into the pulverirer An extension llli'i gix 'upport to a bearii lot in which runs shat 107' having at us further end a second bearing 102 5, mounted on a standard 109. The shaft is shown as provided with a driving gear 110 by which it may be maintained in the desired high speed rotation.

At its interior side the casii'ig or drum 101 is linedwith a cylindrical lining 111 which cooperates with the reducing elements in the reductionot the material. On the shaft 107 is shown a hub 112 carryii'ig a series oi disks 113 upon which are mounted a number of swinging boaters 11 i supported by a pivot shaft 115. p

The far end of the casing is formed with a second head or end wall 116 having a discharge aperture 117 small enough to deliver materials into the interior of the fan to be described. As a means of utilizing the dy- S ill namic energy in the whirling materials to cause them to draw inwardly after traveling axially beyond the pulverizing chamber is shown a modified arrangement, different from that of Figs. 1, 5 and 6, and consisting of-a tapered or conical wall 118 extending from the casing cylindrical wall 101, adja cent to the pulveriz'ing elements, at an inward slant to a point on the end wall 116, substantially adjacent to the central opening 117; and this conical wall 118 may have a lining 119. By this arrangement thefast whirling materials, with high inertia, as the suction from the fan chamber draws them onwardly, are caused gradually to assume whirling paths of less and less diameter, until finally they may readily pass" through the aperture 117 into the fan cham- .vious embodiment, the fan diameter is much less than the beater diameter. In each case the fan diameter is not more than three fourths of the beater diameter, a feature of combination possessing material importance; in the illustration of the fan diameter is shown about two thirds of the beater diameter.-

The features shown in Figs. 7 and 8 which are not illustrated in the main figures are not made the subject of claim herein, but are claimed in a copending application Serial No. 199,528 filed June 17, 1927.

The modification shown in Fig. 9 differs in several respects from that of Figs. 7 and 8. A different type of beaters is shown. Hubs 112, on the shaft 107, carry disks or Webs 113 with paddles 114 at their ends, more analogous to those shown in Fig. 1.

I Two sets of such heaters are shown, spaced from each other, permitting whirl obstructing vanes 6O to be inserted between them, analogous to the vanes in Fig. 1. The conical outlet 118 may also be modified as seen in Fig. 9, by the provisions of fixed vanes serving not only to obstruct rotation and increase pulverization, but also assisting the inward diversion of the whirling .inatters to bring them to the outlet aperture Fig. 10 shows a modification available for use in an embodiment such as that in 7 In this modification the conical outlet portion 118 of the casing, or at least the lining member 119 thereof is shown provided with casing may be maintained.

helical-spiral ribs 130. These are of moder ate height and so inclined that the whirling action of the materials, upon engagement with the ribs tends to promote their advance inwardly along the conical wall to the con-' tracte'd outlet 117. The ribs form grooves 131 between them, and the whirling materials upon reaching these grooves are automatically carried inward and forward to.- ward the discharge. In this way the dy: 112111110 energy of the whirling materials is utilized to bring them inwardly as stated at the outset. By proper designing this action can be increased to such an extent as to give a driving or blowing action, not merely dispensing with a high pressure fan, but in some cases wholly dispensing with the need of an exterior fan or blower, which remark applies also to the form shown in Fig. .6.

The operation may be described as consisting of driving air and the material whirlingly within a chamber at excessive speed, while confining it against peripheral egress during pulverization, namelyby the head or heads with contracted apertures, and utilizing the dynamic energy of the whirling matters for causing them to divert inwardly to the contracted outlet, whereby progressive advance of the material being pulverized may be maintained. Preferably the whirl ing motion referred to is produced by pulverizing means of the impact beater type, rotated at high speed and producing high centrifugal pressure along the chamber, while the deflecting of the matters toward the axis is effected by aspecial' interior ele-' ment or formation located between the beat ing devices and the contracted outlet, whereby low pressure suction means may besufii cient to draw the matters progressively from the chamber, and without impairing the high interior centrifugal pressure. i

The invention may be described as comprising a chambered casing with an operating shaft therein, suitable pulverizing means rotated by the shaft and causing rapid whirling of the air and material being pulverized, the casing having ahead with contracted outletaperture, and means for diverting the whirling matters from a peripheral point inwardly to said outlet aperture, so that progress of the whirling matters through the More specific features are the preferably cylindrical form of easing, with its contracted-apertured heads at both the inlet and outlet ends, and the pulverizing means consisting of impact heaters or paddles mounted on the shaft in an arrangement concentric with the casing. Unless the means deflecting the whirling matters to the outlet is su'flicient to dispense with exterior suction means it is'prefcrable to employ a low pressure fan arranged outside the outlet and operated by the same shaft that rotates the pulverizing means.-

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It will thus be seen that I have described a pulverizing machine embodying the principles and attaining the objects of the present invention; but as many matters of method, operation, structure, combination, arrangement and detail may be variously modified without departing from the principles of the invention it is not .intended to limit the same to such matters except so far as set forth in the appended claims.

lVh-at is claimed is:

1. Apparatus for pulverizing fuel or other materials comprising the combination of means for driving air and material whirlingly within a chamber at excessive speed,

'alls enclosing such chamber and confining the material against peripheral egress at either end or between the ends of the cham her during pulverization, while presenting a contracted outlet, whereby high interior centrifugal pressure of the materials may be maintained during the progress of the whirling materials through the chamber, and means utilizing the dynamic energy of the whirling matters consisting of whirl obstructing surfaces arranged to cause the whirling matters to impact against such surfaces and to spread inwardly to said contracted outlet, whereby progressive advance and delivery of the material being pulven ized may be maintained. 7

A pulverizing machine comprising a chambered casing free from peripheral egress openings and having contracted admission aperture at its inlet end, and contracted discharge opening at its outlet end, an operating shaft therein, pulverizing means rotated by said shaft and causing rapid whirling of the air and material being pulverized so as to produce high centrifugal pressure along the chamber periphery, the casing being interiorly substantially free from obstruction to axial progress of the whirling matters between the pulverizing means and contracted outlet, and tinterior blades adjacent the outlet and arranged to cause the whirling matters to be spread and diverted along sai blades inwardly to said outlet aperture.

3. A pulverizing machine comprising a chambered casing having means for admitting fuel and air to its inlet end, an operating shaft therein, pulverizing means rotated by said shaft and causing rapid whirling of the air and material being pulverized so as to produce high centrifugal pressure along the chamber periphery, the casing formed with a contracted outlet aperture, and being interiorly substantially free from obstruction to axial progress of the whirling matters between the pulverizing means and contracted outlet, means for using the live energy of the whirling matters to assist their diversion from a peripheral pointinwardly to said outlet aperture, and

suction means beyond the outlet aperture arranged to draw the whirling matters from the casing andcomprising a low powerrotary fan, with blades tilted back between 25 and 75 from the radius.

t. A pulverizing machine comprising a casing enclosing a substantially cylindrical chamber free of peripheral egress, a rotary shaft extending a iz'illy through such chanr ber, rotary injipact heaters or said shaft within the casing and extending into proximitv to the chamber peripheral Wall, the casing having a head at each end, with a contracted inlet opening in one head and contracted outlet openingin the other head, both substantially smaller than the chamber diameter, and being interiorly free of sub-- slant-ital obstruction to axial. progress of the whirling matters from the inlet to the contracted outlet, and impact means causing the whirling matters to be diverted inwardly to said outlet opening.

5. A pulveriner as in claim a and wherein is located beyond the outlet a low power suction fan mounted on the same shaft as that carrying the heaters, but of diameter not more than three-fourths of that of the heaters.

6. A pulverizing machine comprising a casing enclosing a substantially cylindrical chamber, a rotary shaft extending axially 'hrmigh such chamber, rotary impact beaters on said shaft within. the casing and extending into pmximity to the chamber peripheral wall, the casing having a head at each end, with a contracted inlet opening in one head and contracted outlet opening the other head, both substantially smaller than the chamber diameter, and being interiorly free of substa? ial obstruction to axial progress of the whirling matters from the inlet to the contracted outlet, means causing the whirling matters to be diverted inwardly to said outlet opening; and a low power suction fan located beyond the outlet mounted on the same shaft as that carrying the healers, and with concave blades tilted back from the radius.

7. A pulverizing machine comprising a casing having contracted inlet and outlet, pulverizing means rotatable in the casing to cause rapid whirling of the air and material to be pulverized, and impact means or blades in the casing adjacent the outlet causing the whirling matters by their whirling energy to divert inwardly to the outlet. l

8. A; pulverizing machine comprising a casing having a contracted outlet, pulverizing means rotatable in the casing to cause rapid whirling of the air and material to be pulverized, and impact means in the casing adjacent the outlet causing the whirling matters bytheir whirling energy to divert inwardly to the outlet, comprising a plural.- ity of blades extending inwardly from the periphery to the outlet whereby the whirling matters may spread inwardly on said blades to the outlet.

9. A pul'verizing machine comprising a casing having a contracted outlet, pulverizing means rotatable in the casing to cause rapid whirling of the air and material to be pulverized, and impact means in the casing adjacent the outlet causing the whirling mat tc rs by their whirling energy to divert in wardly to the outlet, comprising a plurality of fixed blades extending, inwardly from the POFlTllQlY- to the outlet whereby the whirling matters may spread inwardly on said blades to the outlet.

10. A pulverizing machine comprising a casing having a contracted outlet, pulverizing means rotatable in the casing to cause rapid whirling of the air and material to be pulverized, and impact means in the casing adjacent the outlet causing the whirling matters by their whirling energy to divert inwardly to the outlet, comprising a plurality of curved blades extending inwardly from the periphery to the outlet whereby the whirling matters may spread inwardly on said blades to the outlet.

11. A high speed pulverizer comprising a chambered casing, an operatingshaft therein, pulverizing means rotated by said shaft and causing rapid whirling of the air and material being pulverized, the casing having a head with contracted outlet aperture, and means for diverting the whirling matters from a peripheral point inwardly to said outlet aperture consisting of a series of blades extending substantially inwardly from the periphery and arranged to obstruct whirling motion without obstructing axial progress, whereby the whirling matters im- )ac'tlnor on such blades are caused to s read inwardly and thus reach the outlet.

12. A high speed pulverizer comprising a chambered casing having means for admitting fuel and air to its inlet end, an operating shaft therein, pulverizing means rotated by said shaft and causing rapid whirling of the air and material being pulverized so as to produce high centrifugal pressure along the chamber periphery, the casing formed with a contracted outlet aperture, and being interiorly substantially free from axial obstruction to free outgoing progress of the.

whirling matters between the pulverizing means and contracted outlet, and means for using the live energy of the whirling matters to cause their diversion froma peripheral point inwardly to said outlet aperture, consisting of relatively stationary blades excomprising a casing enclosing a. substantially cylindrical chamber having its peripheral portion substantially clear of obstruction to axial flow, a rotary.shaftextending axially through such chamber, rotary impact heaters on said shaft within the casing and extending into proximity to the chamber peripheral wall, the casing having a contracted inlet opening at one end and contracted outlet opening a the other end, said outlet opening being substantially smaller than the chamber diameter, and means assi ting the whirling mat-t rs inwardly to said outlet opening consis 11g of curved blades extending from the periphery substantially to the, center and arranged to be impacted by the whirling matters and thus cause them to spread along the blades to an inward point, without substantialaxial obstruction.

14. A high speed p'ulve'rizcr comprising a chambered casing having means for admitting fuel and air to its inlet end, an operating shaft therein, pulverizing means rotated bysaid shaft and causing rapid whirling of the air and material being pulverized so as to produce high centrifugal pressure along the chamber periphery, the casing formed with a conical outlet portion and contracted aperture, and said conical portion contain ing blades arranged not to obstruct axial progress but to assist the spreading and diverting inwardly of the whirling matters.

15. A pulverizer as in claim 14 and wherein is a suction fan beyond the outlet aperture.

16. A high speed fuel pulverizing ma chine comprising a chambered casing substantially free from peripheral egress openings and from obstruction. to axial progress of the whirling matters and having a con tracted inletaperture and means for admits ting fuel thereto, an operating shaft in'said casing, a first pulverizing device on said shaft near said inlet and causing rapid whirling of the air and material being pulverized, a set of whirl obstructing blades following said first pulverizing device, a second pulverizing device on said shaft between saidblades and the outlet, and said casing formed with a tapered outlet end terminating in a con tracted outlet.

In testimony whereof, I have affixed my signature hereto. 

